A variety of popcorn containers are known in which corn kernels can be popped on or in a conventional stove. One such container is described in U.S. Pat, No. 3,110,233 to Mennen entitled "Apparatus for Shaping Metal Foil." Containers of this general type are, however, not suitable for use in microwave ovens where foil is prohibited. Accordingly, paper containers have been devised for popping corn in microwave ovens, an example being U.S. Pat. No. 3,973,045 to Brandburg et al entitled "Popcorn Package for Microwave Popcorn." It should be noted that these containers are specially constructed for microwave use and generally are not usable in other types of ovens because the paper will burn.
Presently known paper containers for popcorn ingredients do, however, have significant drawbacks. They are permeable by the included shortening or oil and are thus subject to staining and require refrigeration to prevent the migration of the shortening to the outside of the paper. If refrigerated prior to use, they tend to conduct heat through the oven floor, thus creating a cold spot and reducing the effectiveness of the popping action. Moreover, known paper containers tend to be permeable by steam, thus allowing steam to escape with the result that the temperature within the container is lowered and the popping action is less effective, leaving a higher proportion of unpopped kernels. If the container is not permeable by steam it suffers from the disadvantage that the steam, if allowed to remain in the container, may result in the popped kernels becoming too chewy within a very short time. Paper is also less easily torn when compared to metal foil and is therefore difficult to open, especially when hot. Relatively complex and costly to manufacture closure arrangements are therefore required to overcome this problem.